Stringed musical instrument having angularly adjustable string contacting mechanisms



J. W. M BRIDE STRINGED MUSICAL INSTRUMENT HAVING ANGULARLY Nov. 10, 1953 ADJUSTABLE STRING CONTACTING MECHANISMS Filed Sept. 24, 1951 A A M I \Q I @N M INVENTOR. COA/N WMCBQ/DE BY %Arraelvsy- Fatented Nov. 10, 1953 STRINGED MUSICAL INSTRUMENT HAVING ANGULARLY ADJUSTABLE STRING CON TACTING MECHANISMS John W. McBride, Burbank, Califi, assignor to Bantar, Incorporated, Burbank, Calif., a corporation of California Application September 24, 1951, Serial No. 248,051

Claims.

This invention relates to musical instruments of the type described in Patent No. 2,499,194, issued February 28, 1950, to John W. McBride.

It is one of the objects of this invention to improve, in general, the mechanism for adjustably stopping the strings.

The mechanism, as disclosed in said patent, includes one or more rods or tubes mounted upon an axis longitudinally below the string or strings, the rods or tubes extending about this axis in a helical-like manner. Accordingly, as the rod is angularly moved about its axis, as by operation of a key, the point of contact between the rod and the string moves along the length of the wire.

It is another object of this invention to provide a mechanism of this character in which the frictional forces between the rod and the string are substantially eliminated.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of several embodiments of the invention. For this purpose, there are shown a few forms in the drawings accompanying and forming part of the present specification. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Figure 1 is a plan view of an instrument incorporating the invention;

Fig. 2 is an enlarged fragmentary sectional view, taken along a plane corresponding to line 2-2 of Fig. l; and

Fig. 3 is a view, similar to Fig. 2, of a modified form of the invention.

The instrument, in this instance, is shown as having a body I made of any appropriate material. Sets of strings 2 and 3 are tensioned above the body. Since the vibrations generated by the sets of strings 2 and 3 are caused to affect electromagnetic pick-up devices 4 and 5, the body i need not be provided with any resonant cavity. It is provided, however, with a recess 6 which serves to accommodate the operating parts of the instrument, as will be hereinafter described.

The sets of strings 2 and 3 are supported in a manner described in the patent hereinabove identified.

Three strings are shown in each set. However, the number of strings may be chosen at will.

The arrangement in this instance is such that each set of strings 2 and 3 may be stopped or contacted at two spaced points so as to provide a plurality of vibrating string sections. Each section may be individually set into vibration, as by plucking, or the like. The vibrations, in turn, are transformed into electrical impulses by the aid of the pick-up devices 4 and 5 in a well understood manner.

The mechanism for stopping the set of strings 2 is indicated most clearly in Fig. 2. A rod I of circular cross section is provided, having a crank 8 at its right-hand end rotatably mounted upon a shaft it. The center line of the rod I is arranged generally helically about the axis of the shaft I0. The other end of the rod I is provided with a similar crank arm that is mounted for rotation on an axis corresponding to the axis of shaft I0.

Strung on the rod "I are a plurality or rolling elements i I having convex surfaces of revolution. The convexity is quite slight, and is shown exaggerated. As the crank 8 is rotated about the axis of shaft Hi, these rolling elements engage the strings 2 along successive points of contact. This action is entirely similar to that disclosed in said prior patent. Since the elements I I are freely rotatable upon the rod I, these elements I I roll Without material friction over the strings 2. Accordingly, the wear attendant upon the operation of the mechanism is substantially entirely eliminated.

Another round rod I2, constructed similarly to rod i, extends helically around the axis of shaft ID. This rod I2 has a crank arm I3 attached to this shaft. At its left-hand end this rod I2 is similarly pivotally supported by the aid of a structure similar to that disclosed in the hereinabove identified patent. Rod I2 also carries the rolling elements l4, similar to elements I I.

In order to support the shaft l0, use is made of the standards I5 and I6 mounted on the bottom surface of recess 6. Standard I5 rotatably supports the elongated hub ll of crank arm 8, and standard I6 is apertured for the reception of the shaft I0.

Crank 8, and accordingly the rod I, is rotated about the axis of shaft I0 by the aid of a key mechanism, such as described in the patent hereinabove referred to. For example, a gear wheel [8 is shown attached to the hub [1. A helical spring I9 is anchored at one end in the standard I5 and in the other end to the gear [6. This spring tends to return the rod 1 to the initial position indicated in Fig. 1.

In order to adjust the angular position of the helical rod I, a key 20 is utilized. The lower surface of this key has a rack 2| engaging the 5 teeth of the gear Hi. This key is guided in any appropriate manner, as by the aid of a housing 22 covering the key mechanisms.

In order independently to operate the rod 12, a gear 23 is mounted on the shaft I0, and another key mechanism 24 operates the gear.23. A torsion spring 25 is connected to the righthand end of the shaft I0 for urging it toward a beginning position. In the position of Fig. 2, the gear 23 is shown as having been rotated through an angle of approximately 180 from the starting position. In Fig. 1;the rod I2 is shown as lying close to the rod I, corresponding to the initial position of both of these. rods.

By operating either or both-of. thakeys-Zli-or.

24, the angular positions of the rods 1 and [2 may be independently adjusted, exceptasthey may form limits of angular movement for each other.

A similar mechanism, including the rods 7 and I 2 and rolling elements ll andM; may be provided for stopping the-set of strings 3. For this purpose, additional key mechanisms .26 and 21 may be provided.

In the form shown in Fig. 3, the rods 7 and [2 are constructed as in the form shown in Fig. 2. However, the rolling elements 2B,'mounted on the rods 1 and [2, are substantially cylindrical, and. are relatively thin. They are adapted to roll upon-the wire 2 and to rotate upon'the'circular rods 1 and I2 as the. cranks 8 and 13 are rotated.

The inventor claims:

1. In a musical instrument having a tensioned string: a helical-like member having an axisof rotation substantially parallel to the string; a plurality of rolling string contacting elements carried by the member for movement therewith about said axis of rotation rsaid heliealelike member also. mounting, said elements for free about said axis.

. 31; In a musical: instrument having a tensioned string? a helical-like member having a circular cross sectionand an axis of rotation substantially parallel. to the string; a plurality of rolling elements rotatably mounted on the member and havingsurfaces-of revolution for contacting the string; .and..means,for angularly adjusting the member about" said axis.

/ i. In a musical instrument having a tensioned string: a helical-like member having a circular .cross section andan axis of rotation substantially parallel to the string; a plurality of rolling elements rotatably mounted on the member and .having cylindrical surfaces for contacting. the

string; and means for .angularly. adjusting the member about said axis.

5. In a musical instrument having a tensioned string: a helical-like memberhaving a. circular cross section and an axis of rotation. substantially parallel totherstring; a plurality of rolling elements rotatably mounted on the member and having tapered surfaces of revolution for con- =tacting .the string; and means for .angularly adjustingthe member aboutsaid axis.

JOHN W...MCBRIDE.

References Cited in thefile of this patent UNITED STATES PATENTS Name Date .McBride Feb. 5 28, 1950 Number 

